• Journal of Yeungnam Medical Science
• /
• v.38 no.2
• /
• pp.169-174
• /
• 2021

Mucoepidermoid carcinoma (MEC) is the most common malignant neoplasm of the salivary gland, but primary thyroid MEC has rarely been reported and usually has a good prognosis. Herein, I report a case of thyroidal MEC with a poor prognosis in an 82-year-old woman with an anterior neck mass. Ultrasonography and computed tomography revealed a thyroid mass. The patient initially underwent fine-needle aspiration, was diagnosed with malignancy, and underwent a right lobectomy. On gross examination, a 4.0×3.6×2.6 cm-sized ill-defined, unencapsulated, and infiltrative tan to whitish mass with necrosis was identified. Microscopically, epidermoid tumor cell nests or solid sheets were identified. Mucous cells that were positive for periodic acid-Schiff and mucicarmine stains were also identified within epidermoid cell nests. Frequent mitosis and necrosis were observed. Immunohistochemical staining for p40 and p63 was positive, and that for thyroid transcription factor-1 and paired box gene 8 was focally positive. According to the Armed Forces Institute of Pathology grading system for salivary gland MEC, the current case was classified as high-grade MEC. After surgery, the patient suffered from dyspnea due to a remnant neck mass that compressed and obstructed the trachea; therefore, the patient refused further treatment. Thyroidal MECs are considered low-grade with a favorable prognosis, but there are several reported cases of thyroidal MEC with poor prognosis. The current case is a rare presentation of high-grade thyroidal MEC with a poor prognosis.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.12
• /
• pp.1692-1697
• /
• 2023

Staphylococcus aureus integrated with mecA gene, which codes for penicillin-binding protein 2a, is resistant to all penicillins and other beta-lactam antibiotics, resulting in poor treatment expectations in skin and soft tissue infections. The development of a simple, sensitive and portable biosensor for mecA gene analysis in S. aureus is urgently needed. Herein, we propose a dual-toehold-probe (sensing probe)-mediated exonuclease-III (Exo-III)-assisted signal recycling for portable detection of the mecA gene in S. aureus. When the target mecA gene is present, it hybridizes with the sensing probe, initiating Exo III-assisted dual signal recycles, which in turn release numerous "3" sequences. The released "3" sequences initiate catalytic hairpin amplification, resulting in the fixation of a sucrase-labeled H2 probe on the surface of magnetic beads (MBs). After magnet-based enrichment of an MB-H1-H2-sucrase complex and removal of a liquid supernatant containing free sucrase, the complex is then used to catalyze sucrose to glucose, which can be quantitatively detected by a personal glucose meter. With a limit of detection of 4.36 fM for mecA gene, the developed strategy exhibits high sensitivity. In addition, good selectivity and anti-interference capability were also attained with this method, making it promising for antibiotic tolerance analysis at the point-of-care.

• Investigative Magnetic Resonance Imaging
• /
• v.20 no.1
• /
• pp.66-70
• /
• 2016

Introduction: Distant metastases of mucoepidermoid carcinoma (MEC) are reported with the most common sites being the soft tissue of skin, lung, liver, and bone. We report here a very rare case of MEC with multiple metastases to the kidney, adrenal gland, skull and gluteus maximus muscle. Case report: A 63-year-old male patient presented with left-sided headache. Radiologic evaluations including CT and MRI showed ill-defined soft tissue lesion involving the left infratemporal fossa and left sphenoid sinus, and multiple enlarged lymph nodes in neck and mediastinum. PET-CT demonstrated multiple hypermetabolic lesions in and around the left kidney, left adrenal gland, right ischium, right gluteus maximus and skull base. These lesions were confirmed as MEC with multiple metastases through biopsy. Discussion: Only one case of metastasis to the skull has been previously reported, and moreover, there has not been a case of metastatic MEC to the kidney, adrenal gland and gluteus maximus muscle so far in the medical literature. It is important to acknowledge the possibility of every unusual MEC metastases, since the presence of metastasis has statistically significant influence on the survival of MEC.

• Journal of Korea Society of Industrial Information Systems
• /
• v.26 no.1
• /
• pp.11-19
• /
• 2021

The emerging Fifth Generation (5G) network technology brings us a new demand for low latency services. However, it may not be possible for long-distanced cloud computing servers to support users with satisfactory low latency services. For this reason, Multi-access Edge Computing (MEC) technology are gaining attraction since it is designed to provide low latency services to users by placing cloud computing resources to base-stations or mobile switching centers nearby users. Accordingly, it is necessary to verify the deployed containers on the MECs are reliable enough to provide low latency services empirically. For the purpose, we develop a testing tool to verify the reliability as well as network resources status of running MECs by deploying containers on the MECs in a Kubernetes environment.

• Electronics and Telecommunications Trends
• /
• v.31 no.1
• /
• pp.25-35
• /
• 2016

Mobile Edge Computing(MEC)은 무선 기지국에 분산 클라우드 컴퓨팅 기술을 적용하여 다양한 서비스와 캐싱 콘텐츠를 이용자 단말에 가까이 전개함으로써 모바일 코어망의 혼잡을 완화하고, 새로운 로컬 서비스를 창출하는 기술이다. 현재는 European Telecommunications Standards Institute(ETSI)주도로 규격 작업이 진행되고 있으며, 동시에 산업계에서는 LTE 모바일 네트워크에 적용하는 시도들이 이루어지고 있다. 그러나 MEC기술은 Software Defined Network(SDN)/Network Functions Virtualization(NFV) 기술들과 함께 향후 2020년대에 도입될 5G 네트워크의 주요 구성 기술로서 부상하고 있다. 본고에서는 MEC의 개념과 다양한 서비스 시나리오, MEC 플랫폼 구조 및 기술동향 등을 살펴보고, 5G에서의 역할과 앞으로 도전하여야 할 기술적인 과제들에 대하여 분석한다.

• KNOM Review
• /
• v.24 no.1
• /
• pp.20-28
• /
• 2021

Extensive use of social media applications and mobile devices continues to increase data traffic. Social media applications generate an endless and massive amount of multimedia traffic, specifically video traffic. Many social media platforms such as YouTube, Daily Motion, and Netflix generate endless video traffic. On these platforms, only a few popular videos are requested many times as compared to other videos. These popular videos should be cached in the user vicinity to meet continuous user demands. MEC has emerged as an essential paradigm for handling consistent user demand and caching videos in user proximity. The problem is to understand how user demand pattern varies with time. This paper analyzes three publicly available datasets, MovieLens 20M, MovieLens 100K, and The Movies Dataset, to find the user request pattern over time. We find hourly, daily, monthly, and yearly trends of all the datasets. Our resulted pattern could be used in other research while generating and analyzing the user request pattern in MEC-based video caching scenarios.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.4
• /
• pp.41-49
• /
• 2023

This study examined the effect of input substrate concentration on hydrogen production of microbial electrolysis cells. To compare the performance of MEC according to the input substrate concentration, six laboratory-scale MEC reactors were operated by sequentially increasing the input substrate concentration from 2 g/L of sodium acetate, to 4 g/L, and 6 g/L. The current density, hydrogen production, and SCOD removal rate were analyzed, and energy efficiency and cathodic hydrogen recovery were calculated to compare the performance of MEC. The maximum volumetric current density was obtained at 4 g/L condition (76.3 A/m³) and it decreased to 19.0 A/m³, when the input concentration was increased to 6 g/L, which was a 75% decrease compared to the 4 g/L input condition. Maximum hydrogen production was obtained also at 4 g/L condition (47.3 ± 16.8 mL), but maximum hydrogen yield was obtained at 2 g/L input condition (1.1 L H₂/g COD_in). Energy efficiencies were also highest in 2 g/L condition; the lowest result was observed at 6 g/L condition. Maximum electrical energy efficiency was 76.4%, and the maximum overall energy efficiency was 39.7% at 2 g/L condition. However, when the substrate concentration increased to 6 g/L, the performance was drastically decreased. Cathodic hydrogen recovery also showed a similar tendency with energy efficiency, with the lowest concentration condition showing the best performance. It can be concluded that operating at low input substrate concentration might be better when considering not only hydrogen yield but also energy efficiency.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.2
• /
• pp.103-111
• /
• 2008

This study was carried out to investigate the optimal application rate and time of mixed expeller cake (MEC) for the replacement of chemical fertilizer. Dongjin-1, as cultivated rice was used at Fluvio-marine deposit in Honam plain paddy field. Soil chemical properties were improved by the application of MEC. Contents of total nitrogen and organic matter were higher in 70%, 100% plots of basal dressing than standard fertilizer application (SFA) plot. Cation exchangeable capacity was highly increased in 70% plot of basal dressing. Also, the content of organic matter in soil was increased with MEC application. Cation exchangeable capacity, total nitrogen and available phosphate were decreased according to late application time. The content of inorganic nitrogen in soil showed high tendency at more application rate of MEC, and nitrogen mineralization at harvest season have finished in 50%, 70% plots of basal dressing. The content of inorganic nitrogen in soil was increased according to late application time, however it was decreased in the late period of growth. Leaf color value became darker with increased application rate of MEC. Leaf color was dark green in MEC application plots at panicle formation stage, on the other hand, it was light green in 50%, 70% plots of basal dressing at heading stage. SPAD reading value of leaf-color was high during the whole growth stage in MEC application plots. More application rate of MEC showed higher tendency of fertilizer nitrogen absorption. Nitrogen use efficiency was the highest in 70% plot of basal dressing. Absorbed amount of fertilized nitrogen was increased in 10~15days before transplanting and nitrogen use efficiency was high according to the late application time. The ratio of perfect kernel and the content of protein on hulled rice showed high tendency at the less application rate of MEC. The ratio of head rice on milled rice showed high tendency at the less application rate of MEC. Rice yield increased 4% in 100% and 70% plots of basal dressing compare with SFA ($5.18Mg\;ha^{-1}$) plot respectively. Ear and culm length of rice were long according to the late application time, while the numbers of spikelet and ear were increased and the percentage of ripened grain was decreased. Rice yield was increased 2~5% in all MEC application plots compared to SFA plot and especially, increased 10~15days before transplanting in application plots. The optimal application rate and time of MEC on normal paddy field in plain were concluded that 70% basal dressing and 10~15days before transplanting

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.1
• /
• pp.188-210
• /
• 2022

As a promising technique to support tremendous numbers of Internet of Things devices and a variety of applications efficiently, mobile edge computing (MEC) has attracted extensive studies recently. In this paper, we consider a MEC-assisted peer-to-peer (P2P) mobile communication system where MEC servers are deployed at access points to accelerate the communication process between mobile terminals. To capture the tradeoff between the time delay and the energy consumption of the system, a cost function is introduced to facilitate the optimization of the computation and communication resources. The formulated optimization problem is non-convex and is tackled by an iterative block coordinate descent algorithm that decouples the original optimization problem into two subproblems and alternately optimizes the computation and communication resources. Moreover, the MEC-assisted P2P communication system is compared with the conventional P2P communication system, then a condition is provided in closed-form expression when the MEC-assisted P2P communication system performs better. Simulation results show that the advantage of this system is enhanced when the computing capability of the receiver increases whereas it is reduced when the computing capability of the transmitter increases. In addition, the performance of this system is significantly improved when the signal-to-noise ratio of hop-1 exceeds that of hop-2.

• Korean Journal of Head & Neck Oncology
• /
• v.30 no.2
• /
• pp.79-82
• /
• 2014

Salivary gland tumors take possession of almost 5% in head and neck malignancies. Among these, mucoepidermoid carcinoma(MEC) is most common malignany in major salivary glands(12-29%) and the parotid gland is most predilection site. Intra-oral MEC has a tendency to various locations, and the predilection sites are palate, cheek, mandible, lip and tongue in order of frequency. A few cases of MEC are occurred in with retromolar trigone, oropharynx, and ectopic salivary gland. Recently, we experienced a-65-year old woman with retromolar trigonal mass, and she was finally diagnosed as MEC. We report it with review of literature.